Adolescence is a time of notable neurobehavioral transitions, with increases in peer-directed social interactions common among adolescents of a variety of species. It is during adolescence that alcohol intake becomes normative in humans, with a significant number of adolescents engaging in high (binge) levels of use. Most adolescent use of alcohol occurs in a social context, with adolescents reporting that a key motive for their drinking is for social facilitation. Using an animal model of adolescence, adolescent rats likewise often drink substantially more than mature rats, and are uniquely sensitive to ethanol-induced increases in peer-directed social interactions. This ethanol-induced social facilitation is not normally evident in adult rats, but emerges in adults and becomes even more pronounced in adolescents following chronic stress. Despite the critical role that the social context plays in adolescent alcohol use, little is known of the social neuroscience of this use - e.g., whether ethanol enhances the rewarding properties of social stimuli to make social interactions particularly rewarding for adolescents, or whether ethanol exposure in a social context increases ethanol's hedonic impact among adolescents. These possibilities may not be mutually exclusive and will be explored, along with potential neural substrates for these effects, using an animal model of adolescence in the rat in the proposed work. Effects of ethanol on the rewarding value of social stimuli will be examined in Aim 1 through studies of social motivation (approach and anticipation), social affect, and social buffering, while Aim 3 will use similar measures to assess whether sensitization to ethanol-induced social facilitation induced by chronic stress is related to an enhancement of the effect of ethanol on social reward. Effects of a social context on ethanol's aversive and appetitively rewarding properties will be examined in Aim 2 through studies of place conditioning, along with assessing the impact of a social context on ethanol intake in a voluntary, limited access situation. Candidate brain regions potentially contributing to enhanced ethanol/social reward expression during adolescence will be identified in Aim 4. The proposed work will further understanding of how the social context influences adolescent alcohol use, identify candidate neural regions contributing to these adolescent-characteristic interrelationships, and help inform strategies for the use of social context as a protective, rather than a risk factor for adolescent alcohol use.